Any hidden prob's doing head gaskets?

[Bellicose]

Well i got my coolant system pressure tested the other day, has been losing a bit of coolant and gauge sits higher since putting in a new radiator bout 2months ago.

Looks like it's a head gasket (bubbles coming up through radiator and over flow tank is always empty)

So went and bought a head set (Top end set) and new head bolts $273 nzd all up.

It's a 3800 in a '93 VR.

Now my question is this, is there any tricks or problems i may come up against when doing the job?

I've never had to do them on a 3.8 before.

I've been rebuilding my own engines since i was 15 (now 42), i know my way 'round engines, i hold a record of sorts lol. Red 202 in an HQ, out of car - new pistons, rings, bearings, cam - back in car and running perfectly in 1 hours 57 minutes.

cheeRS.

[bpefi]

Apparently they crack in the heads between the seats - so its worth getting it checked out - would have thought it would be hard to do a head gasket in one of these..being cast iron heads & block. You could have a coolant leak there also - apparently inlet manifold gaskets let go at times...


That's pretty good time - one of my mechanics drove a push car at speedway for me, a HJ wagon with a 308 in it - dropped a rod on the start of speedway - had to tow it back by himself on a trailer - he had a new donk in ( had a spare) & back to racing by 8.30 or so. Thought that that was pretty good also.

[hsv91ss]

unless it is overheating I would more then likely say Inlet Manifold gasket as I had the same thing it was using coolant and temp sat a little higher then normal (didn't have the bubbles though) and it was the Inlet gasket they are common to fail.

Also had sludge in the radiator when I ran my finger along the inside top which made me think it was the head but no water in oil.

[db_notso]

i would have pressurized the cooling system and taken the plugs out
then leave pressured for 30mins (engine cold) then crank and see if water came out plug holes
is very backyard method but anyways works well as a start to diagnose faulty head gaskets

some of this may sound silly to say to you but anyways!~
on these motors need to check head for cracks and pitting and valve seats for wear
check block deck with straight edge and head with straight edge (check warped)
basically they need to be rebuilt but i know of motors fixed on the cheap with just head bolts and gaskets and never failed again
also i recomend replacing the thermostat as they have a habit of sticking when the head gaskets leak on these ( not sure exactly why i suspect the temperatures too high)
apart from that pretty straight forward motors to do headgaskets just as a precaution all rods etc that you remove try and refit them to the same place on installation as they were in originally
as they wear together and some valve components have been known to have metal with different amounts of alloy steel etc can if not fitted to same places cause an excessive clearance issue long term
causing the whole job to have to be redone if this fault happens its about 2 years later if motor is low kilometers

[bpefi]

i would have pressurized the cooling system and taken the plugs out
then leave pressured for 30mins (engine cold) then crank and see if water came out plug holes
is very backyard method but anyways works well as a start to diagnose faulty head gaskets

some of this may sound silly to say to you but anyways!~
on these motors need to check head for cracks and pitting and valve seats for wear
check block deck with straight edge and head with straight edge (check warped)
basically they need to be rebuilt but i know of motors fixed on the cheap with just head bolts and gaskets and never failed again
also i recomend replacing the thermostat as they have a habit of sticking when the head gaskets leak on these ( not sure exactly why i suspect the temperatures too high)
apart from that pretty straight forward motors to do headgaskets just as a precaution all rods etc that you remove try and refit them to the same place on installation as they were in originally
as they wear together and some valve components have been known to have metal with different amounts of alloy steel etc can if not fitted to same places cause an excessive clearance issue long term
causing the whole job to have to be redone if this fault happens its about 2 years later if motor is low kilometers

Thermostats fail when they have been severely overheated usually - no wax left in them...

[db_notso]

yeah i realise overheat but for some reason even when gauge hasnt gone high and the head gasket blown in these ones the thermostat sticks on me after repair
i "think" its because air gets trapped around the hole the coolant temp sensor sits into and the air reads a different temp than coolant not as hot due to pressure in system
not 100% sure why just know its a pain to redo the coolant after all that work!~

[Bellicose]

Thanks for the input guys.

Temp now sits on 1/4 but used to sit at 1/8 (fist mark above cold) when driving, goes up to 1/2 when sitting in traffic but fan comes on at 1/2 and temp' drops straight away.

Also the idle is little rough but not bad.

There is a strong smell of coolant in the cab when driving somtimes but there is no coolant on the floor so don't think it's the heater tap or heater core. Have no carpet in the ute so would notice any coolant leaks inside car. Took out carpet to fit new seats and waiting on my new door seals before i refit carpet.

[Z2TT]

Bit weird I thought VS Fans always come on at 3/4. My car is always at about 1/4 or so when cruising, and at the lights gets to 3/4 and the fan come son.
Who knows maybe they revised the instrument cluster to only get upto 1/2 when fans come on to stop making people think it's overheating.

[Brett_jjj]

My VSV6 sits around the second to third mark on the temp gauge when driving on the highway,a little bit more than this around town,but if I stop at the lights or whatever and let it idle,it goes to half way on the temp gauge,then the fan kicks in and drops it to about a quarter,then the fan shuts off again.It just repeats this process if left idling.

[GTP 85]

If you havent already done the job... while you have the heads off get them checked for cracks. They crack between the valve seats. Make sure the deck faces are spotless and the head faces are spotless. A nip of the head faces to clean them up wont hurt 20 thou

Just make sure they are torqued down to spec and rechecked after a few days